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Cond
Syntax
Cond B_1 Then E_1 EndCond
Cond B_1 Then E_1 Elsif B_2 Then E_2 Elsif ... EndCond
Cond B_1 Then E_1 Elsif B_2 Then E_2 Elsif ... Else E_r EndCond
Cond(B_1,E_1,B_2,E_2,...,E_r)
where the B_i's are boolean expressions and the E_i's are expressions.
Summary
conditional expression
Description
If B_n is the first in the sequence of B_i's to evaluate to TRUE,
then E_n is returned. If none of the B_i's evaluates to TRUE, then
Null is returned. The construct,
Elsif B Then E
can be repeated any
number of times. Note: be careful not to type
Elseif
by mistake (it
has an extraneous
e
).
The difference between
Cond
and
If
is that
Cond
is an expression
which may be assigned to a variable; each of the E_i's is an
expression, not a general sequence of commands (as their analogues in
If
might be).
example
Define Sign(A)
Return Cond A>0 Then 1 Elsif A=0 Then 0 Else -1 EndCond;
EndDefine;
Sign(3);
1
-------------------------------
Define PrintSign(A)
Return Cond(A>0,"positive",A=0,"zero","negative");
End;
PrintSign(3);
positive
-------------------------------
See Also